A semiconductor light emitting device having a structure in which a p-side electrode and an n-side electrode are formed on one surface side of a semiconductor layer including a light emitting layer is known. In this semiconductor light emitting device, a light of the light emitting layer can be reflected by the electrode and extracted from the other surface side. In this case, it is desired that the electrode having a high light reflectance be spread with a large area on the one surface side.